What determines how much interest you earn

The amount of interest you earn depends on three things: the annual percentage yield (APY) your bank offers, how much money you have in the account, and how long it stays there. A bank with a 4.5% APY will pay you more than a bank with 0.01% APY on the same balance. The difference between accounts at the same bank can be hundreds of dollars per year.

APY varies widely and changes constantly. Right now, some online banks offer 4% to 5% APY on savings accounts, while traditional brick-and-mortar banks often offer less than 0.5%. The rate your bank pays you today may be lower next month. Banks raise and lower rates based on what the Federal Reserve does with its benchmark interest rate, which it adjusts several times per year.

Interest compounds, meaning you earn interest on your interest. If you have $10,000 at 4.5% APY and leave it untouched for a year, you earn about $450 in interest. If you leave that $10,450 in the account for another year at the same rate, you earn about $470 in interest the second year—not $450—because you're earning interest on the $450 you already earned.

Key Takeaways

  • Your interest earnings depend on the APY your bank offers, your account balance, and how long the money stays in the account.
  • APY rates vary from under 0.5% at traditional banks to over 5% at some online banks, and these rates change frequently.
  • Interest compounds, so you earn interest on the interest you've already earned, which increases your total over time.
  • You can calculate your expected earnings by multiplying your balance by the APY, though the actual amount depends on how often interest is credited.
  • Moving money to a higher-APY account can significantly increase what you earn without changing how much you save.

How to calculate what you'll earn

The basic calculation is straightforward: multiply your account balance by the APY. If you have $5,000 in an account with 4% APY, you'll earn about $200 per year. If you have $10,000 at the same rate, you'll earn about $400 per year.

The actual amount varies slightly depending on how often the bank credits interest to your account. Most banks credit interest daily or monthly. Daily compounding means you earn slightly more than monthly compounding because interest gets added to your balance more frequently. The difference is usually small—a few dollars per year on typical balances—but it adds up over time.

If you want to know the exact amount before opening an account, ask the bank for the effective annual rate (EAR) or look for an online calculator that factors in the compounding frequency. Many banks publish this information on their website or will tell you over the phone.

Why rates differ between banks

Online banks typically offer higher APY than traditional banks because they have lower overhead costs. They don't maintain physical branches, so they can pass savings to customers through higher interest rates. A bank with one branch in your city might offer 0.25% APY, while an online bank with no physical locations offers 4.75% APY on the same type of account.

Banks also offer different rates based on account type. A money market account might pay more than a regular savings account at the same bank. A high-yield savings account is designed specifically to pay more interest than a standard savings account. Credit unions sometimes offer rates competitive with online banks, though availability depends on your membership.

The bank's cost of borrowing money also affects what it pays you. When the Federal Reserve raises its benchmark rate, banks can borrow money more cheaply and often raise the rates they pay depositors. When the Fed lowers rates, banks typically lower what they pay you. This is why your APY might drop even if you do nothing—the bank is responding to broader economic changes.

How often interest is added to your account

Banks credit interest on different schedules. Some credit daily, some weekly, some monthly, and some quarterly. The schedule matters because interest that's credited more often compounds more often, earning you slightly more money over time.

Daily compounding is the most common at online banks. This means the bank calculates interest on your balance every day and adds it to your account. Monthly compounding is common at traditional banks. Quarterly compounding is less common but still exists at some institutions.

The difference between daily and monthly compounding on a $10,000 balance at 4% APY is roughly $10 to $15 per year. It's not huge, but it's real money. If you're comparing two banks with similar APY, choosing the one with daily compounding is the better choice.

What happens when rates change

When your bank lowers its APY, the new rate applies to your existing balance when ready. You don't have to do anything. If you had $10,000 earning 4.5% and the bank drops the rate to 3.5%, you start earning at the lower rate right away. This is why monitoring your rate matters—if your bank's rate drops significantly below what competitors offer, moving your money to a higher-paying account makes financial sense.

When rates rise, your bank may or may not raise what it pays you. Banks are slower to raise rates than to lower them. If the Federal Reserve raises rates but your bank doesn't, you're losing money by staying put. Check your bank's current rate against what online banks are offering. If there's a gap of 1% or more, the math favors switching.

You can move money between banks without penalty. Savings accounts have no early withdrawal fees or lock-in periods. You can transfer your balance to a higher-paying bank whenever you want. The transfer usually takes three to five business days.

The difference between APY and interest rate

APY and interest rate are related but not identical. The interest rate is the percentage the bank pays on your balance. The APY is the interest rate plus the effect of compounding over a year. If a bank advertises 4% APY, that's the total you'll earn in a year if you leave the money untouched.

Banks are required to show you the APY, not just the interest rate, so you can compare accounts fairly. This is why you see APY on savings account advertisements and disclosures. It's the number that matters for your decision.

Frequently Asked Questions

Do I pay taxes on savings account interest?

Yes. Interest earned on savings accounts is taxable income. Your bank will send you a Form 1099-INT at the end of the year if you earned $10 or more in interest. You report this on your tax return. The tax rate depends on your overall income and tax bracket.

Can I lose money in a savings account?

No, your principal is protected. Savings accounts are insured by the FDIC (Federal Deposit Insurance Corporation) up to $250,000 per account holder per bank. You cannot lose the money you deposit. Interest rates can go down, but your balance cannot go below what you put in.

Is it worth moving my money to get a higher rate?

It depends on your balance and the rate difference. If you have $50,000 and can move it from 0.5% to 4.5% APY, you'll earn about $2,000 more per year. The transfer takes a few days and costs nothing. For most people with balances over $5,000, the higher rate is worth the effort.

What's the highest APY I can find right now?

Rates change frequently and vary by bank. Online banks currently offer rates ranging from 4% to 5.35% APY on savings accounts, though this changes as the Federal Reserve adjusts its benchmark rate. Check current rates on banking comparison websites or directly with banks you're considering.

Does keeping money in savings longer earn more interest?

Yes, because of compounding. Money that sits in the account for two years earns more total interest than money that sits for one year, assuming the rate stays the same. However, the interest rate itself doesn't change based on how long you keep the money—only the total amount earned increases because interest compounds on a larger balance.